Can somebody please explain what the exhaust valve thing (just before the slip on pipe) is for. Maybe to help the bike get through noise or emmisions?? Mine is a UK bike, not even sure you have this in the States?

My bike, an 07 FXDC, SE air cleaner with Khrome Werks slip-ons and PC111 is running quite well but sometimes feels a bit fluffy on acceleration (not pulling as cleanly as I would like). I am thinking a complete exhaust (rather than slip-ons) would run cleaner - any experiences please ?

 

I think what your refering to is the cross over tube. I believe it helps with backpressure and performance. The stock pipes in us do have them also. But some aftermarket pipes have them but some dont. My v&h's dont for example. But my buddies sideshots for the sportsters do.

 

Thanks Josh, but what I'm trying to find out about is something like a valve which is opened by means of a cable when the engine reaches a certain r.p.m. (no tacho so not sure what r.p.m.).

 

on the international models there is a valve thats there for the foreign pollution contraols. its got a cable on it. none of the domestic models have it. i think its there to build backpressure for some reason. its described in the service manual..

scott

 

Hi Papa, i too am from UK the exhaust valve you talk about is briefly to keep down the exhaust note at lower revs where the noise / pollution test is done. Then when you raise the revs outside of this "test" zone the exhaust valve opens to release more power / sound.
I have fitted a full Vance & Hines system. The exhaust valve and all its cable and wiring then comes off the bike along with the stock system. Its an easy job with no issues, the electrics to the exhaust valve on removal require a blanking plug which is ready available so as not to set off warning codes on your instruments.
With the full system and PC111 with Big Sucker i had it set up on a dyno and pulls really well very linear. Could be the map that your using is not quite right, iv,e no experience of running with the exhaust valve but i,d have thought i should be ok with the right map.
Hope this helps, best wishes.

 

Hi Cornishman, thanks for your reply - I think you hit the nail on the head and confirmed my suspicions, I can feel a full system coming on!
Where did you get your system from?
Thanks

 

I picked up the V&H Shortshots on ebay, they were used but nearly new. If / when i buy another system or pretty much anything else i,ll probably buy from the USA. The dollar has strengthened a little lately but there are still bargains out there.
The service from the 15 or so items i,ve bought from the USA so far has been great so i,d rather give them my money. Its worth trying several places as the shipping can vary a lot, one place i,ve used more then once with very fast service is Robs cycle supply ( robw23 ) on ebay.
Best wishes